Add-on Dev: How to iterate the properties of a type and read/write values
You can iterate through the annotations to get and set each prop. 

&gt;&gt;&gt; settings = C.scene.my_addon
&gt;&gt;&gt; settings.__annotations__.keys()
&gt;&gt;&gt; for p in settings.__annotations__.keys():
...     getattr(settings, p)
...     setattr(settings, p, True)